opt_logo.gif (12610 bytes)

Multi-Element Laser Diode
Collimating and Focusing Lenses

pdf.gif (231 bytes) MULTIELE.PDF  (160K) Click on the file name to download an Adobe PDF file covering this section.

For the most demanding application, a three or four element spherical lens achieves a level of optical performance difficult to obtain with any single element lens. To assure diffraction-limited performance, start by collimating the diode with one of the Optima 336 Series multi-element lenses. The 336 Series lenses are computer optimized to minimize aberrations, maximize coupling efficiency, and function over a broad range of wavelengths and normal manufacturing tolerances. The lenses can be used with most visible and near-infrared laser diodes and are currently used in a wide array of products including the following:

The 336-1027 is an excellent general purpose collimating lens, its small physical size is compatible with both 5.6mm and 9.0mm diameter laser diodes, making a very compact assembly. A relatively large numerical aperture (NA) of 0.47 captures a large percentage of the beam from most common laser diodes – coupling efficiencies typically range from 91% to 95%. The 336-1027 is available with two standard MgF2 anti-reflection coatings designated as: -660 for visible laser diodes (633nm to 750nm); -785 for use with most near-infrared diodes (750nm to 980nm). A new version

Multiple Element Spherical Lens Specifications:

Part Number 336-1027-660 336-1027-785 336-1027-450
Unit price (Qty 1-49) $29.20 $50.80
Description Collimating Lens
Conjugate Distance Infinite
Design Wavelength 660 nm 785 nm 450 nm
Focal Length 4.488 mm 4.527 mm 4.334 mm
Working/Source Distance 2.18 mm 2.22 mm 2.06 mm
Numerical Aperture .451 .447 .467
Clear Aperture 4.3 mm 4.3 mm 4.3 mm
F# 1.04 1.05 1.01
Field Size (diameter) * 0.078 mm 0.079 mm 0.076 mm
AR Coating, MgF2 660 nm 785 nm 450 nm
Transmission >92% >93% ~89%
Cover Glass Thickness 0.25 ~ 0.30 mm
Cover Glass Index (n) 1.52023 1.51107  
Cell material and finish Aluminum, black anodized
Cell Dimensions
(diameter x length)
6.4 dia. x 6.3 mm

* The Field Diameter of a collimating lens defines the largest size emitter the lens will accommodate and still maintain other optical specifications, such as the wavefront aberration specification. 

Example:  If the field diameter specification is 100 microns, then the size of the laser diode emitter must be less than 100 microns in either axis.  Generally, when using lower powered diodes (1mW to 100mW) the emitter size is not a concern, as the emitter is typically only a few microns in the perpendicular or parallel axis.  When using higher power diodes, diodes arrays, or LED’s the emitter can be significantly larger – emitters larger than 100 microns are common.

Top of Page Home e-mail

© Optima Precision Inc.
Last modified: March 31, 2019